Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “VENTILATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,675 records · Page 93Linked to original sources

[Performance studies of 6 new anesthesia ventilators: bench tests].

OBJECTIVE: To assess the pneumatic performances of six new anaesthesia ventilators. STUDY DESIGN: Bench test study. MATERIAL: The study included one ventilator operated by an electric motor: ABT 5300 (Kontron); four ventilators of "bellows-in-bottle" category: ADU version 97 (Datex-Ohmeda); Aestiva 3000 (Datex-Ohmeda), Kion (Siemens), the two versions of Julian (Dräger); and an original ventilator devised for quantitative, or self-regulating target controlled inhalation anaesthesia, with a totally closed circuit, made of four ventilating chambers: PhysioFlex (Dräger). METHODS: The bench test included a passive lung model with adjustable compliance and resistances, and flow and pressure gauges. The accuracy of volume and pressure measurements was tested in various conditions of resistance and compliance. RESULTS: Pneumatic performance and accuracy were satisfactory, even in severe ventilatory conditions. All the ventilators, except ABT 5300 and Julian 1, have a compliance compensation system permitting to deliver and to maintain a constant tidal volume under various conditions of downstream load, particularly under maximal load condition. Variations of tidal volume with the increase of the fresh gas flow are negligible. CONCLUSION: Recent technological progress has improved pneumatic performance of anaesthesia ventilators and the marketed models are more homogeneous at present. Ergonomics and training for the use of the machine are becoming major criteria for the global assessment and the choice of a ventilator.

Airway Resistance↗

Prophylactic chlorhexidine oral rinse decreases ventilator-associated pneumonia in surgical ICU patients.

BACKGROUND: Pneumonia is one of the most common nosocomial infections in hospitalized patients. The risk of nosocomial pneumonia increases with age, severity of acute illness and preexisting co-morbid conditions. Ventilator-associated pneumonia (VAP) significantly increases morbidity, length of stay, resource utilization and mortality. The purpose of this study was to determine whether adherence to a ventilator weaning protocol (WP) and the use of chlorhexidine gluconate (CH) oral rinse for oral hygiene would decrease the incidence of VAP in surgical ICU patients. METHODS: A prospective study was conducted over a period of 10 months (October 1998-July 1999) in surgical ICU patients requiring mechanical ventilation (n = 95). During the first 5 months, a WP was applied to all patients requiring mechanical ventilation. During the following 5 months, a CH 0.12% oral rinse administered twice daily was added to the protocol, initiated on ICU admission in all intubated patients. The data collection included age, gender, race, risk factors, co-morbid conditions, severity of the acute illness (APACHE II) at admission, duration of ventilation, ICU and total-hospital length of stay, and incidence of VAP and in-hospital mortality rates. Both WP and WP+CH groups were compared using the National Nosocomial Infection Surveillance (NNIS) and hospital databases as historic controls. RESULTS: The institution of the WP alone led only to a slight decrease in the incidence of VAP but a significant reduction in the median duration of mechanical ventilation by 40% (4.5 days, p < 0.008). The addition of CH to the WP led to a significant reduction and delay in the occurrence of VAP (37% overall, 75% for late VAP, p < 0.05). The median duration of mechanical ventilation in this group was similar to that of the WP group. There was no significant difference in the overall hospital or ICU length of stay between the groups. CONCLUSIONS: Improved oral hygiene via topical CH application in conjunction with the use of a WP is effective in reducing the incidence of VAP and the duration of mechanical ventilation in surgical ICU patients.

Aged↗

Adaptive support ventilation for fast tracheal extubation after cardiac surgery: a randomized controlled study.

BACKGROUND: Adaptive support ventilation (ASV) is a microprocessor-controlled mode of mechanical ventilation that maintains a predefined minute ventilation with an optimal breathing pattern (tidal volume and rate) by automatically adapting inspiratory pressure and ventilator rate to changes in the patient's condition. The aim of the current study was to test the hypothesis that a protocol of respiratory weaning based on ASV could reduce the duration of tracheal intubation after uncomplicated cardiac surgery ("fast-track" surgery). METHODS: A group of patients being given ASV (group ASV) was compared with a control group (group control) in a randomized controlled study. After coronary artery bypass grafting during general anesthesia with midazolam and fentanyl, patients were randomly assigned to group ASV or group control. Both protocols were divided into three predefined phases, and weaning progressed according to arterial blood gas and clinical criteria. In phase 1, ASV mode was set at 100% of the theoretical value of volume/minute in group ASV, and synchronized intermittent mandatory ventilation mode was used in group control. When spontaneous breathing occurred, ASV setting was reduced by 50% of minute ventilation (phase 2) and again by 50% (phase 3), and the trachea was extubated. In group control, the ventilator was switched to 10 cm H2O inspiratory pressure support (phase 2), then to 5 cm H2O (phase 3) until extubation. RESULTS: Forty-nine patients were enrolled. Sixteen patients completed the ASV protocol, and 20 the standard protocol; 7 patients were excluded in group ASV and 6 in group control according to explicit, predefined criteria. There were no differences between groups in perioperative characteristics or in the doses of sedation. The primary outcome of the study, that is, the duration of tracheal intubation, was shorter in group ASV than in group control (median [quartiles]: 3.2 [2.5-4.6] vs. 4.1 [3.1-8.6] h; P < 0.02). Fewer arterial blood analyses were performed in group ASV (median number [quartiles]: 3 [3-4] vs. 4 [3-6]), suggesting that fewer changes in the settings of the ventilator were required in this group. CONCLUSIONS: A respiratory weaning protocol based on ASV is practicable; it may accelerate tracheal extubation and simplify ventilatory management in fast-track patients after cardiac surgery. The evaluation of potential advantages of the use of such technology on patient outcome and resource utilization deserves further studies.

Aged↗

Optimizing intrapulmonary perfluorocarbon distribution: fluoroscopic comparison of mode of ventilation and body position.

OBJECTIVE: Partial liquid ventilation with the perfluorochemical, perflubron, has been shown to improve lung mechanics and enhance gas exchange in the treatment of severe acute lung injury. However, the most effective strategy to provide optimal intrapulmonary distribution of perflubron has not been fully accessed. The objective of this study was to examine the effect of body position (supine vs. rotational) and mode of ventilation (conventional mechanical ventilation [CMV] vs. high-frequency oscillatory ventilation [HFOV]) on perflubron distribution and oxygenation improvement. DESIGN: Prospective, randomized, animal trial. SETTING: Research laboratory at a university medical center. SUBJECTS: Twenty healthy piglets (4.5-6.6 kg). INTERVENTIONS: Subjects underwent repetitive saline lavage to achieve a uniform degree of lung injury and then were randomized to either CMV or were converted to HFOV. Within each ventilator group, animals were randomized to supine positioning (S) or rotational positioning with alternation between supine and prone position (R) during incremental dosing of three 5-mL/kg doses of perflubron. MEASUREMENTS AND MAIN RESULTS: Arterial blood gas tensions, hemodynamic variables, and the oxygenation index were recorded after each dose of 5 mL/kg. Lateral cinefluoroscopic images after each dose were digitized for computer analysis of density. A density index was calculated for a 2-cm2 window in three dorsal and three ventral lung regions. Uniformity of distribution was calculated by comparing the mean density among the six regions. Oxygenation improvements were compared between groups. There were no significant differences in hemodynamic variables or gas exchange after lung injury in the four groups. Rotational positioning produced significantly more uniform perflubron distribution during both CMV and HFOV. This effect was independent of the mode of ventilation. The mean ventral density index was affected by rotating position and HFOV mode of ventilation after 10 mL/kg of perflubron, and rotating position was affected only after 15 mL/kg of perflubron. There was a significant reduction in the oxygenation index from baseline to end lavage in both CMV groups, as well as all of the animals that were rotated. CONCLUSION: Perflubron is more uniformly dispersed when dosed in a rotational fashion with alternation between supine and prone position during incremental dosing. This effect is independent of mode of ventilation. There was no relationship between oxygenation improvements and nondependent perflubron distribution. CMV and rotating dosing both led to a significant decrease in the oxygenation index after a 15 mL/kg dose of perflubron. This information has important impact on the future development of dosing strategies and clinical trial design.

Animals↗

Comparison of anaesthesia ventilators using a lung model.

The ventilatory performance of six anaesthesia ventilators (Alphavent Drägerwerk; MCM 801 Ventilator Dameca; Ohmeda 7000 Ventilator and Ohmeda 7800 Ventilator Ohmeda; Servo Ventilator 900 D and Ventilator 710 Siemens-Elema) was tested in a lung model and compared with the ventilatory performance of the old Engström 300 (Gambro Engström). The lung model consisted of one tracheal tube, two bronchial tubes which could be partially occluded, and two lungs (glass jars filled with water to a suitable compliance). Dialled (set) minute volume was compared to recorded minute volume. Gas distribution between obstructed and non-obstructed lung was calculated. All ventilators had a linear relationship between dialled and measured volume. Only the Servo Ventilator 900 D produced a gas distribution which was as good as, or better than that produced by the Engström 300.

Airway Obstruction↗

Isocapnic high frequency jet ventilation: dead space depends on frequency, inspiratory time and entrainment.

Twelve healthy pigs were ventilated with high frequency jet ventilation via a Mallinckrodt HiLo jet tube. The expired gas was led to a conventional ventilator and CO2 analyzer which were used to measure CO2 elimination. There was no bias flow, so that the jet entrained only expired gas, i.e. rebreathing occurred. Frequency was varied between 2 and 11 Hz and the duration of inspiration, as a fraction of the ventilatory cycle (Ti/Ttot), from 5 to 20%. The minute ventilation, Vjet, delivered by the jet ventilator was adjusted to maintain a constant PaCO2. At 2 Hz and a Ti/Ttot of 5%, Vjet was of the same magnitude as ventilation during conventional intermittent positive pressure ventilation, and the total dead space fraction, VD/VT was 0.32. Both increasing frequency at a constant Ti/Ttot, and increasing Ti/Ttot at a constant frequency, increased VD/VT which was maximal (0.8) at 11 Hz and a Ti/Ttot of 20%. When entrainment was blocked, tidal jet volume had to be greatly increased. The continuous measurement of CO2 elimination was found to be useful for maintaining isocapnia when the jet ventilator setting was changed.

Animals↗

In vitro performance characteristics of high-frequency oscillatory ventilators.

This study aimed to examine the performance characteristics of four high-frequency oscillatory-type ventilators, using an in vitro model of the intubated neonatal respiratory system. Each ventilator was examined across its operative range of settings and at varying model lung compliance (C) and resistance. The oscillatory pressure waveform was measured at the airway opening (Pao). Tidal volume (VT) and flow were determined from pressure changes within the model lung (DeltaPA). The spectral content of the Pao waveform differed between ventilators. The maximum ventilator VT ranged from 3.7 to 11.1 ml at 15 Hz and a mean airway pressure (Paw) of 12 cm H(2)O to oscillate a model lung (C = 0.4 ml/cm H(2)O) through a 3.0-mm internal diameter (i.d.) endotracheal tube (ETT). A small drop in C was associated with a decrease in VT and marked increase in DeltaPA from 0.1 to 0.8 ml/cm H(2)O. The influence of C on VT and DeltaPA and the pressure cost of ventilation (DeltaPA/f.VT(2)) was dependent on the oscillatory frequency, ETT inner diameter, and the specific ventilator used. Substantive differences exist between oscillatory ventilators that need to be considered in their clinical application. The rapid establishment of optimal lung volume and oscillatory frequency is important in minimizing barotrauma during high-frequency oscillatory ventilation.

Biomechanical Phenomena↗

Leak compensation in positive pressure ventilators: a lung model study.

Leak compensating abilities of six different positive pressure ventilators commonly used to deliver noninvasive positive pressure ventilation, including the bilevel positive airway pressure (BiPAP) S/T-D and Quantum (Respironics Inc, Murrysville, PA, USA), 335 and O'NYX (Mallinckrodt Inc, St Louis, MO, USA), PLV 102 (Respironics), and Siemens Servo 900C (Siemens Inc, Danvers, MA, USA). Using a test lung model, compensatory capabilities of the ventilators were tested for smaller and larger leaks using the assist/control or timed modes. Back-up rate was 20 min(-1), inspiratory pressure was 18 cmH2O, and expiratory pressure was 5 cmH2O. It was found that even in the absence of air leaking, delivered tidal volume differed substantially between the ventilators during use of pressure-targeted modes, depending on inspiratory flows, inaccuracies in set versus delivered pressures, and inspiratory duration. Also during pressure-targeted ventilation, increasing the tI/ttot up to, but not beyond, 0.5 improved compensation by lengthening inspiratory duration, whereas use of a sensitive flow trigger setting tended to cause autocycling during leaking, interfering with compensation. Leaking interfered with cycling of the BiPAP S/T, inverting the I:E ratio, shortening expiratory time, and reducing delivered tidal volume. Volume-targeted modes achieved limited compensation for small air leaks, but compensated poorly for large leaks. To conclude, leak-compensating capabilities differ markedly between ventilators but pressure-targeted ventilators are preferred for noninvasive positive pressure ventilation in patients with substantial air leaking. Adequate inspiratory flows and durations should be used, triggering sensitivity should be adjusted to prevent autocycling, and a mechanism should be available to limit inspiratory time and avoid I:E ratio inversion.

Airway Resistance↗

A computer-controlled ventilator weaning system.

Weaning of patients from mechanical ventilation is a time-consuming, labor-intensive process. Because most weaning decisions are based on objective data, we tested a computer-directed weaning system on postoperative patients. We developed an automatic, computer-controlled ventilator weaning system which interfaces a laptop computer to a ventilator and a pulse oximeter. The laptop computer program accesses patient data through the ventilator and pulse oximeter to make weaning decisions. The computer directly controls the ventilator through an interface developed for this system. We tested the system in nine postoperative patients who met the following criteria: negative inspiratory force less than or equal to -20 cm H2O, vital capacity greater than 10 ml/kg, inspired oxygen concentration less than or equal to 40 percent, and satisfactory arterial blood gas parameters (pH between 7.32 and 7.48, PCO2 between 32 and 48, and oxygen saturation greater than or equal to 90 percent). The computer decreased the SIMV rate by 2 breaths/min every 5 min until a rate of 2 breaths/min was reached, then decreased pressure support by 4 cm H2O every 5 min as long as the patient met the following criteria: respiratory rate between 8 and 25 breaths/min, minute ventilation between 6 and 14 L, and pulse oximeter oxygen saturation greater than or equal to 90 percent. If unsatisfactory weaning criteria were noted, the system automatically returned the patient to the previous weaning level. We successfully weaned nine patients using the system. Additional studies are underway to determine if this system can be used in medical patients. We believe this computer-controlled ventilator weaning system can be used successfully in patients requiring mechanical ventilation and may decrease the time and cost associated with the care of these patients.

Adult↗

A prospective, randomized comparison of an in-line heat moisture exchange filter and heated wire humidifiers: rates of ventilator-associated early-onset (community-acquired) or late-onset (hospital-acquired) pneumonia and incidence of endotracheal tube occlusion.

PURPOSE: To compare the performance of an in-line heat moisture exchanging filter (HMEF) (Pall BB-100; Pall Corporation; East Hills, NY) to a conventional heated wire humidifier (H-wH) (Marquest Medical Products Inc., Englewood, Colo) in the mechanical ventilator circuit on the incidence of ventilator-associated pneumonia (VAP) and the rate of endotracheal tube occlusion. METHODS: This report describes a prospective, randomized trial of 280 consecutive trauma patients in a 20-bed trauma ICU (TICU). All intubated patients not ventilated elsewhere in the medical center prior to their TICU admission were randomized to either an in-line HMEF or a H-wH in the breathing circuit. Ventilator circuits were changed routinely every 7 days, and closed system suction catheters were changed every 3 days. HMEFs were changed every 24 h, or more frequently if necessary. A specific endotracheal tube suction and lavage protocol was not employed. Patients were dropped from the HMEF group if the filter was changed more than three times a day or the patient was placed on a regimen of ultra high-frequency ventilation. The Centers for Disease Control and Prevention (CDC) criteria for diagnosis of pneumonia were used; early-onset, community-acquired pneumonia was defined if CDC criteria were met in < or =3 days, and late-onset, hospital-acquired pneumonia was defined if criteria were met in >3 days. Laboratory and chest radiograph interpretation were blinded. RESULTS: The patient ages ranged from 15 to 95 years in the HMEF group and 16 to 87 years in the H-wH group (p=not significant), with a mean age of 46 years and 48 years, respectively. The male to female ratio ranged between 78 to 82%/22 to 18%, respectively, and 55% of all admissions were related to blunt trauma, 40% secondary to penetrating trauma, and 5% to major burns. There was no difference in Injury Severity Score (ISS) between the two groups. Moreover, there was no significant difference in mean ISS among those who did not develop pneumonia and those patients who developed either early-onset, community-acquired or late-onset, hospital-acquired pneumonia. The HMEF nosocomial VAP rate was 6% compared to 16% for the H-wH group (p<0.05), and total ventilator circuit costs (per group) were reduced. There were no differences in duration of ventilation (mean+/-SD) if the patient did not develop pneumonia or if the patient developed an early-onset, community-acquired or a late-onset, hospital-acquired pneumonia. Moreover, total TICU days were reduced in the HMEF group. In addition, the incidence of partial endotracheal tube occlusion was not significantly different between the H-wH and the HMEF groups. CONCLUSIONS: The HMEF used in this study reduced the incidence of late-onset, hospital-acquired VAP, but not early-onset, community-acquired VAP, compared to the conventional H-wH circuit. This was associated with a significant reduction in total ICU stay. Disposable ventilator circuit costs in the HMEF group were reduced compared to the H-wH group in whom circuit changes occurred at 7-day intervals. CLINICAL IMPLICATIONS: The use of the HMEF is a cost-effective clinical practice associated with fewer late-onset, hospital-acquired VAPs, and should result in improved resource allocation and utilization.

Adolescent↗

Volume-guaranteed ventilation.

Pressure-limited, time-cycled ventilation has been the primary mode of ventilation for neonates for several decades. But the realization that volume rather than pressure causes ventilator-induced lung injury has led to the development of new strategies for ventilation. Volume guarantee is a mode of ventilation that automatically adjusts the inspiratory pressure to achieve a set tidal volume according to changes in lung compliance or resistance or the patient's respiratory drive. Volume-guaranteed ventilation delivers a specific, preset volume of gas, and inspiration ends when it has been delivered. This mode of ventilation requires careful attention to the infant and to ventilator settings.

Animals↗

Invasive and noninvasive pediatric mechanical ventilation.

Both invasive and noninvasive mechanical ventilation techniques are inherent to the care of most patients admitted to intensive care units. Despite the everyday use of mechanical ventilation for thousands of patients and the availability of thousands of reports in the medical literature, there are no clear and consistent guidelines for the use of mechanical ventilation for pediatric patients. In many areas data are lacking, and in other areas data are extrapolated from studies performed with adult subjects. Despite the variability in views about mechanical ventilation, 2 themes are consistent. First, modern pediatric respiratory care requires a substantial institutional commitment for state-of-the-art management of the mechanically ventilated patient. Second, a team approach involving physicians, nurses, and respiratory therapists is essential. This review highlights some of the major issues affecting the pediatric patient who requires invasive or noninvasive mechanical ventilation. These issues are pertinent to critical care clinicians because one of the most common reasons for admission to an intensive care unit is the need for mechanical ventilation. Furthermore, the duration of mechanical ventilation is one of the major determinants of the duration and cost of an intensive care unit stay.

Child↗

Hemodynamic effects of high-frequency oscillatory ventilation in halothane-anesthetized dogs.

Hemodynamic effects of spontaneous ventilation, intermittent positive-pressure ventilation (IPPV), and high-frequency oscillatory ventilation (HFOV) were compared in 6 dogs during halothane anesthesia. Anesthesia was induced with IV thiamylal Na and was maintained with halothane (end-tidal concentration, 1.09%). During placement of catheters, dogs breathed spontaneously through a conventional semiclosed anesthesia circuit. Data were collected, and dogs were mechanically ventilated, using IPPV or HFOV in random order. Ventilation was adjusted to maintain PaCO2 between 38 and 43 mm of Hg during IPPV and HFOV. Cardiac index, aortic blood pressure, and maximum rate of increase of left ventricular pressure were significantly (P less than 0.05) less during HFOV than during spontaneous ventilation, whereas right atrial and pulmonary artery pressure were significantly greater during HFOV than during spontaneous ventilation. During IPPV, only the maximum rate of increase of left ventricular pressure was significantly less than that during spontaneous ventilation.

Anesthesia↗

Efficacy of noninvasive positive pressure ventilation by facial and nasal mask in hypercapnic acute respiratory failure: experience in a respiratory ward under usual care.

Noninvasive intermittent positive pressure ventilation (NIPPV) via a nasal or facial mask is an effective treatment of hypercapnic acute respiratory failure (ARF) caused by various diseases preventing endotracheal intubation (ETI) in 60-90% of patients. The technique can even be effective for routine care, using simplified ventilators, after adequate personnel training. In this study, the effectiveness, in a general respiratory ward under usual care, of NIPPV delivered by simplified ventilators via facial or nasal mask was evaluated in 40 patients with hypercapnic ARF (NIPPV group) and compared to 30 matched historical patients under conventional treatment (Conv group). Compared to conventional treatment, NIPPV was associated with a reduction in negative events such as ETI and mortality together (17% versus 60%, p = 0.0002), but not mortality alone (5% versus 13.5%, NS) or in the mean (+/- SD) length of the hospital stay (27.31 +/- 16.2 versus 27.5 +/- 20.5 days, NS). Patients treated with NIPPV, but not those treated conventionally, showed significant and rapid changes in arterial carbon dioxide tension (Pa,CO2) and pH between baseline and subsequent evaluation after 6 h, 1, 3 and 7 days and upon the discharge from hospital; in fact, in the NIPPV group after 6 h the arterial pH had risen from 7.30 +/- 0.062 to 7.35 +/- 0.066 and Pa,CO2 had decreased from 9.4 +/- 1.5 to 8.5 +/- 1.1 kPa. In the Conv group pH was stable at 7.29 and Pa,CO2 had risen from 9.39 +/- 1.8 to 9.43 +/- 1.6 kPa. In the NIPPV group no differences were found in the admission characteristics between patients successfully and unsuccessfully ventilated, although a significant improvement was observed after 1 h, for pH from 7.31 +/- 0.058 to 7.36 +/- 0.57 and Pa,CO2 from 9.2 +/- 1.3 to 8.3 +/- 1.3 kPa in successfully ventilated patients. In patients who failed to be ventilated with NIPPV pH worsened, from 7.26 +/- 0.069 to 7.24 +/- 0.078 and Pa,CO2 from 10.0 +/- 2.1 to 11.3 +/- 2.5 kPa. In conclusion, addition of noninvasive positive pressure ventilation delivered by nasal or face mask to conventional therapy, reducing the need for endotracheal intubation, may improve the management of patients with hypercapnic acute respiratory failure as compared to conventional therapy alone, even when instituted in a respiratory ward under usual care with simplified ventilators.

Aged↗

Risk factors associated with development of ventilator associated pneumonia.

OBJECTIVE: To assess the risk factors associated with development of ventilator associated pneumonia (VAP). DESIGN: A case control study. PLACE AND DURATION OF STUDY: Intensive Care Unit (ICU) at the Aga Khan University Hospital, Karachi, between January 1999 and June 2000. PATIENTS AND METHODS: All patients with assisted mechanical ventilation were assessed for the development of VAP. Risk factors associated with development of VAP were determined. Adult patients who developed pneumonia, 48 hours after ventilation, were called cases while those who did not develop pneumonia were called controls. RESULTS: Seventy (28%) out of 250 mechanically ventilated patients developed VAP (rate of VAP was 26 cases per 1000 ventilator days). Shock during first 48 hours of ventilation (odds ratio (OR), 5.95; 95% confidence interval (CI), 2.83-12.52), transport out of ICU during mechanical ventilation (OR, 6.0; 95% CI, 2.92-12.37), re-intubation (OR, 4.23; 95% CI, 2.53-9.85), prior episode of aspiration of gastric content (OR, 3.07; 95% CI, 1.35-7.01), and use of antibiotics prior to intubation (OR,2.55; 95% CI, 1.20-5.41) were found to be independently associated with a higher risk of developing VAP. Gram negative organisms and Staphylococcus aureus were responsible for over 90% of cases. Patients with VAP had higher crude mortality rate (57.1%) compared with controls (32.2%). CONCLUSION: Ventilator associated pneumonia is associated with a high mortality. This study has identified risk factors associated with VAP.

Adult↗

Superimposed high-frequency jet ventilation for laryngeal and tracheal surgery.

OBJECTIVE: To describe our experience with superimposed high-frequency jet ventilation (SHFJV), which does not require any endotracheal tubes or catheters, for performing laryngeal and tracheal surgery. DESIGN: A case series of 500 patients. SETTING: A university medical center. PATIENTS: Four hundred sixty adult patients and 40 children in a consecutive sample who required laryngeal or tracheal surgery under SHFJV. INTERVENTIONS: The SHFJV uses 2 jet streams with different frequencies simultaneously and is applied using a jet laryngoscope. Ventilation was performed with an air-oxygen mixture, and intravenous agents were used for anesthesia. Arterial blood gas values were analyzed. MAIN OUTCOME MEASURES: Reported values of oxygenation and ventilation during the application of SHFJV and laryngotracheal surgery. RESULTS: In 497 patients, adequate oxygenation with a mean +/- SD PaO2 of 91.8 +/- 22.9 mm Hg and ventilation with a PaCO2 of 29.7 +/- 5.5 mm Hg were achieved using SHFJV. The average duration of the application of ventilation was 27 minutes, and the longest duration was 118 minutes. No complications due to the ventilation technique were observed. Laser surgery was performed in 150 patients. CONCLUSIONS: The use of SHFJV in combination with the jet laryngoscope provides patients with sufficient ventilation during laryngotracheal surgery. Even in patients at high risk because of pulmonary or cardiac disease, this technique can be applied safely. In patients with stenosis, the ventilation is applied from above the stenosis, reducing the risk of barotrauma. The SHFJV can be used for tracheobronchial stent insertion, and laser can be used without any additional protective measures.

Adolescent↗

Decrease in ventilation time with a standardized weaning process.

OBJECTIVE: To test the hypothesis that standardizing the process of weaning from mechanical ventilation would decrease ventilation times and length of stay in a surgical intensive care unit. DESIGN: Comparison of historic ventilation times with physician-directed weaning with those obtained with protocol-guided weaning by respiratory therapists. SETTING: Urban, teaching surgical intensive care unit with open admission policy and no dominant diagnosis related group. RESULTS: From January 1, 1995, through December 31, 1995, 378 patients who underwent physician-directed weaning from a ventilator had 64488 hours of ventilation, compared with 57796 ventilation hours in 515 patients with protocol-guided weaning (April 1, 1996, through May 31, 1997). The mean hours of ventilation decreased by 58 hours, a 46% decrease (P<.001). The length of hospital stay decreased by 1.77 days (29% change), while the Acute Physiology and Chronic Health Evaluation III score remained at 50 to 51. The number of reintubations did not change. The marginal cost savings was $603580. CONCLUSION: Protocol-guided weaning from mechanical ventilation leads to more rapid extubation than physician-directed weaning and has great potential for cost savings.

APACHE↗

Protocol-driven ventilator management in a trauma intensive care unit population.

HYPOTHESIS: The use of weaning and sedation protocols affects the intensive care unit (ICU) course of a trauma population. DESIGN: Nonrandomized before-after trial. SETTING: A level I trauma center. PATIENTS: Three hundred twenty-eight consecutive trauma patients receiving mechanical ventilation treated in the ICU between October 1, 1997, and November 1, 1999. INTERVENTION: Sedation and weaning protocols were used to treat patients receiving mechanical ventilation during the second year of this study. MAIN OUTCOME MEASURES: Self-extubation rates, ventilator days, number of ICU days, and charges. RESULTS: There were 168 patients in the preprotocol group (year 1: October 1, 1997, to October 31, 1998) and 160 patients in the postprotocol group (year 2: November 1, 1998, to November 30, 1999). The groups were similar in age (P =.68), Injury Severity Score (P =.06), and Glasgow Coma Scale score (P =.29). There were no differences in self-extubation rates (P =.57), ventilator days (P =.83), ventilator charges (P =.83), number of ICU days (P =.67), or ICU charges (P =.67) between the 2 groups. No statistical difference was identified in any of these categories when long-term ventilator patients (defined as ventilator length of stay > or =3 SDs above the mean) were excluded. CONCLUSIONS: Use of weaning and sedation protocols did not affect the measured outcomes in this study. These findings may reflect difficulties inherent in the protocols or with their utilization. Further subgroup analysis focusing on ventilator-associated pneumonias and mortality may demonstrate benefits not identified herein.

Adult↗